Glucose syrups with a DE (Dextrose Equivalent) around 42 is widely used in industry as an ingredient in products such as hard boiled candy, toffees, fudge, fondant and the like.
Traditionally 42 DE glucose syrups are produced by standard acid conversion. A starch slurry is initially acidified to pH 2, and is then pumped into a continuous reactor which operates at elevated temperature and pressure. After a period of time the liquor is returned to atmospheric conditions, neutralised, clarified, decolourised and concentrated to the final syrup. Such acid converted glucose syrup profile shown in FIG. 1 reduce the tendency of sucrose to crystallise, they slow down the tendency to shell-graining and they contribute to the characteristic "mouth-feel".
Today also enzymatic conversion of starch into glucose syrup has been suggested. However, such glucose syrups typically have a sugar spectrum which is quite different from the traditionally used 42 DE acid converted glucose syrup.